Midi Keeps Following Me
It's everywhere you look these days, even your new guitar amp. There's no escape, but there's no need to run. Just hook up your guitar amp to your computer's midi interface and download some new guitar distortion programs from the internet. The acronym Midi stands for musical instrument digital interface. This is, at best, a vague description considering the amount of digital technology in music equipment these days. The best way to describe Midi is that it allows one electronic device to control another. Originally implemented in the early 80s, Midi's first use was to allow keyboards and drum machines (electronic music instruments, of course!) to be used in integrated systems that include sound modules and sequencers, but now its on just about everything. What's a sound module? Whats a sequencer? Why on earth do my reverb unit and my digital mixing console have midi jacks?
A sound module is essentially a keyboard with no keys on it. In other words, Its just the brain of a keyboard with, at bare minimum, a place to output the sound and a way to be played by something else that has the ability to communicate with it. The method of communication is, you got it, Midi. You play a note on a keyboard, the info about the note you pressed travels out a small jack and through a cable into the sound module and you hear a note from the module as if it was the keyboard, except for the fact that the sound comes from the outputs of the module. Why would I want to bother with having a keyboard with no keys? Size and price for starters. Generally they are much cheaper than keyboards and a fraction of the size. How many keyboards can you physically play at one time? I challenge anyone to play more than four. (via the common appendages). I will never have too many sounds to play however and I have 11 sound modules (try fitting 11 keyboards into a room or budget). Also instruments besides keyboards can transmit midi, such as guitars with special pickups or electronic drum kits, even electronic clarinets. This allows you to play any sound available to keyboards and modules from a non-keyboard instrument. Yes, you can play drums from a guitar.
A sequencer records and plays back musical performance data (huh?) Basically, it records songs in the form of notes and other controllers (such as sustain pedals and pitchbend levers) rather than in an audio form. That means they record and play back midi data. If Beethoven were around he could sit down at a keyboard and play the ninth symphony with a sitar sound. Then he could speed the tempo up to 225 bpm and decide to play back his performance with a tuba sound instead. If his keyboard is multitimbral he can listen to the tuba play back while recording an oboe on another track. He can then go into measure 48 of the song and remove just the A# from beat 3. A sequencer usually provides complete control and manipulation for midi data allowing any aspect of playback to be changed. There are tons of advantages to midi recording such as quantizing, which takes note timing and makes it perfect or near perfect. Midi data takes up almost no space because it is only performace data and not the sound. It is common to fit up to 30 songs on a single floppy disk. A keyboard/module must usually be present to play the song back though which is played by the sequencer sending the notes in real time to the keyboard/module. Sequencing would not be instead of audio recording of course, because you can't play midi files (sequences.... from sequencers) in your car stereo. Sequencing, though, is a typical first step of many modern produced songs that contain midi capable instruments before mixing and making a cd. (or vinyl for you djs out there) It is important to note, though, that midi-fied instruments like guitar's actual sound is not transmitted, only the notes. The recorded notes will only play back a keyboard or sound module and not the guitar's own sound. Your sound module may have guitar sounds inside and although this seems like technologic irony at its best, there are occasions where you'd want to play fake guitar sounds on a real guitar.
Midi can also pass along some other cool information besides notes and performance data. It can provide real time start, stop and sync functions. For instance, let's say you have a drum machine and a computer hard disk recording system. Midi can be used to synchronize the drum machine along with the song. I'd like to see you try to press play on the computer at the same millisecond as the drum machine while compensating for the different electronic delays that occur between the mouse click and the drum machine play button. Drum machines are really just a sequencer with some drum sounds and preprogrammed sequences. Sequencers come in many different shapes and flavors, some of which don't record note (or drum hit) data at all. Digital mixing consoles often have sequencers inside for recording fader movements and other automated mixing controls. The midi jacks allow these mixing sequences to be synced along with the recorder in the same manner as a drum machine. Also, many non-midi sound producing or controlling devices such as effect units have midi jacks too. Often, they can be edited by remote control in full detail from a computer, essentially, giving them a full monitor as a screen rather than that inch worth of modified calculator screen it probably has. You can also often download presets from the internet through midi. Also, during a song the effect can also be made to switch, for example, from reverb to chorus at measure 38 because of the ability of sequencers to record a nifty thing called a program change. Program changes can even be used to make complex automated lighting arrangements for live shows and clubs.
Midi is just about anywhere a modern music engineer or songwriter can look. With the internet explosion midi has exploded too. You can download 78 versions of Carlos Santanna's Evil Ways for free (and any other song you've heard of) and rearrange it with any keyboard/module generated instruments you can dream up or even just use the drum track and discard the rest. Karaoke people love midi files because of these abilities. The web loves Midi files because they take almost no space and download instantly. Most computers these days have midi file players built in. (rather cheezy ones though) People post there own original and cover "general" midi files all over the web. (General midi files play back with the appropriate sounds from any keyboard/module) It's pretty big time. A friend of mine has a web site dedicated to original midi files and he gets an average of 20,000 hits (people viewing pages of his site) per day! People download some 10,000+ midifiles from his site and some of them upload their own works. I think I remember even seeing sequencing programs and midi interfaces for HP palmpilots. I'm not kidding! I'm expecting to see midi jacks on my tv anyday now, and I plan to sequence my toaster with program changes.